No pictures are available yet, but this probably means that Musk will show pictures of real hardware in his September presentation.

As I mentioned on another thread this is 1 year earlier than we have assumed for such engine and tests. This makes our estimates for NET BFR first launch test conservative by as much as 1 year moving the possibility of a BFR to exist as early as 2019/2020.

SpaceX is moving faster than we expect. This is surprise number 2 for this year in relation to Mars after the RD mission date.

No pictures are available yet, but this probably means that Musk will show pictures of real hardware in his September presentation.

As I mentioned on another thread this is 1 year earlier than we have assumed for such engine and tests. This makes our estimates for NET BFR first launch test conservative by as much as 1 year moving the possibility of a BFR to exist as early as 2019/2020.

SpaceX is moving faster than we expect. This is surprise number 2 for this year in relation to Mars after the RD mission date.

One of the advantages of a privately held company is the ability to keep projects secret. No SEC paperwork giving away what's going on.

Interesting. Has the upper stage co-fire @ takeoff to increase T/W. Problem with Rvacs there.What I like is someone not showing some BFR/BFS that is some ridiculous height like past Reddit posts I've seen elsewhere. A >10m wide BFR gets very heavy quickly with propellant. I'm confident that the reveal will be short and stout.

In the discussion thread it appears that MCT co-fire may not be necessary, since his concept has a first stage which delivers enough power to give the whole stack a thrust-to-weight similar to Saturn 5/Apollo (around 1:1.15).

Sea Level ISP 350 seconds seems too high so the BFR will not perform to that level assumed.On the other hand you don't need the same Km/sec to RTLS as you launched because some of the launch velocity vector is vertical. It's not pure horizontal velocity. Yes, you need some additional -X delta V to actually fly back.

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“When it looks more like an alien dreadnought, that’s when you know you’ve won.”

There's some indirect evidence that it may be one of several options they'll consider.

I don't disagree that it will be or already was considered; there are many possibilities that will be discarded as not optimum or unworkable.Certainly no evidence that it will be used on Red Dragon, which would be the obvious opportunity to test it...

It's nearly certain that some sort of deployable drag enhancement device will be used for MCT. None will be used on Red Dragon, which is not at all a reason to think it won't be used on MCT.

I don't have any particular belief that SpaceX will use something like HIAD. I don't envision they will. But you dismiss the possibility far too easily.

GS:

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Figuring out how to do this on Mars is going to be a challenge, part of why we need retro-propulsion on Mars, more predictable than aerodynamics.

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"If we shared everything [we are working on] people would think we are insane!"-- SpaceX friend of mlindner

The shuttlecock style interstage is quite interesting. How close do you all feel this is to what we will see in Sept?Also, is it possible to build control surfaces into that? How does it give control authority like grid fins?

Maybe coborop believes that all the control authority needed can come from the main engines and a couple of cold thrusters. I however think that they haven't invested in know-how of grid fins without also using them for the MCT. As I see it they deliver much better targeting ability than the shuttle cock, even though the shuttle cock probably ensures better passive stability.

Sea Level ISP 350 seconds seems too high so the BFR will not perform to that level assumed.On the other hand you don't need the same Km/sec to RTLS as you launched because some of the launch velocity vector is vertical. It's not pure horizontal velocity. Yes, you need some additional -X delta V to actually fly back.

I think that's 350s for the SL engine operating in vacuum (e.g. booster stage near MECO). SpaceX is proposing 321s at SL and 363s in vacuum for the SL engine, so 350s is probably conservative.

With a prototype Raptor engine going into test the preliminary (concepts/requirements/definition) phase is drawing to a close with the detail design phase starting now. With a good model of what the Raptor will be able to achieve (ISP, thrust, engine bell size, T/W, etc) the specific capabilities of the two elements BFR and BFS will be set by the Sept reveal. Think of that as the PDR for those familiar with US government development program milestones. Although this is a pure commercial development it still has the same phases in its development: - preliminary (concept/specifications),- critical (detail design, manufacture "drawings", prototypes, tooling, etc for all elements of the vehicles),- production of test articles, and - finally production of flight articles.

And with the drawing of this preliminary design phase to a close so dose this thread's speculation about concepts and capabilities. It will then refocus on the details not revealed in Sept.

Sea Level ISP 350 seconds seems too high so the BFR will not perform to that level assumed.On the other hand you don't need the same Km/sec to RTLS as you launched because some of the launch velocity vector is vertical. It's not pure horizontal velocity. Yes, you need some additional -X delta V to actually fly back.

I think that's 350s for the SL engine operating in vacuum (e.g. booster stage near MECO). SpaceX is proposing 321s at SL and 363s in vacuum for the SL engine, so 350s is probably conservative.

Yes, we know that. His calculations use 350seconds ISP for the 1st stage BFR, so as I said his BFR model over performs what we know about a SL methalox engine. The "average" ISP for stage one is most likely under 350s.

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“When it looks more like an alien dreadnought, that’s when you know you’ve won.”

There's some indirect evidence that it may be one of several options they'll consider.

I don't disagree that it will be or already was considered; there are many possibilities that will be discarded as not optimum or unworkable.Certainly no evidence that it will be used on Red Dragon, which would be the obvious opportunity to test it...

It's nearly certain that some sort of deployable drag enhancement device will be used for MCT. None will be used on Red Dragon, which is not at all a reason to think it won't be used on MCT.

I don't have any particular belief that SpaceX will use something like HIAD. I don't envision they will. But you dismiss the possibility far too easily.

Are HIADs considered to be a ballute? At the 46:00 in the Small Sat keynote address by Qwynne Shotwell, she's says "Retropropulsion is really the answer. As opposed to parachutes, aero foils, ballutes and those things. Atmospheres are much too dynamic. Retroprpulsion really is the answer. In addition it will scale."

They probably shouldn't be. Although ballutes are capable of generating drag, they are not capable of generating negative lift. Also they, and parachutes aerofoils only appear to be intended for supersonic and subsonic flight regimes, rather than hypersonic.

They probably shouldn't be. Although ballutes are capable of generating drag, they are not capable of generating negative lift. Also they, parachutes and aerofoils only appear to be intended for supersonic and subsonic flight regimes, rather than hypersonic.

HIADs are none of the above, but they do suffer from the same issues when it comes to precision landing.

Also, some airfoils are quite capable of hypersonic flight. The Shuttle, Buran, and a number of lifting body designs were airfoils designed/tested and/or flown at hypersonic reentry speeds.

"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

SpaceX is switching to carbon fibers from aluminum as it develops heavy rockets for carrying people and large quantities of material. A lighter body would allow more cargo to be loaded, which would cut transport costs.

SpaceX is switching to carbon fibers from aluminum as it develops heavy rockets for carrying people and large quantities of material. A lighter body would allow more cargo to be loaded, which would cut transport costs.

Combined with fast transits, rad problem could be largely mitigated. PMF could (will) be best ever by far...

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Update: On Tuesday evening SpaceX would not confirm that a large deal had been reached. "Toray is one of a number of suppliers we work with to meet our carbon fiber needs for Falcon rocket and Dragon spacecraft production, and we haven’t announced any new agreements at this time," a company spokesman told Ars. "As our business continues to grow, the amount of carbon fiber we use may continue to grow."

Sliced out some posts that weren't really MCT to a new thread. When proposing new ideas let's stay focused on what is within the bounds of what we know already... if your idea doesn't fit what has already been said it probably doesn't belong here.

"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY